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Red-breasted Merganser
|-| Information = __NOEDITSECTION__ The handsome Red-breasted Merganser, also known as the "sawbill," is a welcome sight along coastlines during the winter. Appearance Red-breasted Mergansers measure 20.1-25.2 inches (51-64 centimeters) in length, 28.2-47.6 ounces (800-1350 grams) weight, and 26.0-29.1 inches (66-74 centimeters) in wingspan. This merganser is a large, slim, and long-bodied diving duck with a fairly long neck and a long, thin, serrated bill. Their feet are located far back in their bodies, making life hard for them on land. One of the Red-breasted Merganser's notable features is a shaggy-looking double crest. The colorful male sports a metallic-green head, white neck band and wing patches, a red bill and eyes, and a reddish, black-speckled breast, for which the bird is named. The female is mostly gray with an orange-brown head. In flight both sexes have a prominent white lower wing panel. Occurrence The Red-breasted Merganser frequents salt water more than any other North American merganser, typically occurring near the coasts. It breeds in northern regions around the globe, from Europe to Asia to North America, where it nests from Alaska, across northern Canada, down to the Great Lakes, then east to the Maritimes on the Atlantic coast. In North America, this duck is a medium- to short-distance migrant, moving south in small flocks to winter on the Great Lakes and along both coasts as far south as northern Mexico and the Florida Keys. Life History Diet Red-breasted Mergansers dive underwater in search of a wide variety of small fish and fish eggs, occasionally capturing crustaceans as well. While they seem to prefer foraging in shallower water, Red-breasted Mergansers will hunt wherever prey is abundant, using a variety of feeding strategies, including floating at the surface, looking underwater as they go; diving in search of prey; and diving in formation to herd schooling fish such as herring. Nesting Unlike other mergansers, which usually nest in tree cavities, Red-breasted Mergansers nest on the ground in a variety of sites near water with vegetation. They nest alone or in colonies often with gulls and terns. Once mated, the female merganser (or hen) nests and raises her brood alone. The female creates a depression on the ground that she covers with dead grasses, forming a shallow bowl. She plucks down feathers from her breast to help insulate the nest. Hen mergansers often lay eggs in the nests of other mergansers and sometimes those of other duck species as well. Broods in North America average five to 24 eggs, but as many as 56 eggs have been observed in a nest, thanks to brood parasites. They lay one brood per year. The olive-bluff eggs measure 2.3-2.7 inches (5.8-6.8 centimeters) in length and 1.7-1.9 inches (4.3-4.7 centimeters) in width. Incubation period is 28-35 days. At hatching, the hatchlings are covered with down, eyes open. They are able to leave the nest within 24 hours. Red-breasted Mergansers exhibit high nest-site fidelity, and several closely related females may nest near each other. After hatching, broods often combine into “nurseries” or “crèches,” with one female caring for a large group, while other hens take the opportunity to feed and rest away from their broods. Behavior Red-breasted Mergansers are among the fastest flying ducks, clocking speeds of up to 81 miles per hour. To get airborne though, they need a running start. Their legs are positioned near their rear making it difficult to walk on land, but are an asset when diving. Red-breasted Mergansers do not defend territories and are social birds year-round. Red-breasted Mergansers form mated pairs each season during their spring migration, usually starting in March. Groups of males gather to display for a single female, but these roving groups of male mergansers are not considered leks, as they don't congregate in a specific location. Courting males salute a female with head held high and then curtsy to the female by tipping up and putting their rear in the air with bill held high. In response to the male's gesture, the female often jabs him with her bill. In the latter, the male drops his bill forward, then flicks it up while rising chest-high in the water before dropping back, accompanied by a backwards kick. Courting males also shake their head side to side to get the attention of a female. Once the female accepts the male she stretches her neck out while holding her bill down and then lowers her neck again in a bobbing motion. They form a monogamous bond for the breeding season, but the male takes off at the beginning of incubation, leaving the female to tend the young alone. Males head to secluded waters to molt their feathers before migrating south while females tend to molt near the breeding site. Sounds When displaying, females give a raspy or croaking call while males give a catlike yeow-yeow. In flight, females make a harsh gruk. Otherwise Red-breasted Mergansers are generally silent. Conservation Red-breasted Mergansers are common and their populations were stable between 1966 and 2015, according to the best estimates of the North American Breeding Bird Survey (although the species’ northern breeding grounds are partially outside of the survey’s coverage area). Aerial surveys on the breeding grounds estimated the total merganser population (Red-breasted and Common) at half a million in 2017, 15% higher than the long-term average from 1990–2016. Partners in Flight estimates the global breeding population of Red-breasted Mergansers at 370,000. The species rates an 11 out of 20 on the Continental Concern Score, which means it is not on the Partners in Flight Watch List and is a species of low conservation concern. However, declines in North American Red-breasted Merganser populations have been noted, likely due to a variety of reasons. Some populations may be threatened by wetland destruction, and climate change can make nests near water increasingly vulnerable to flooding. Red-breasted Mergansers and other diving ducks are frequently caught and drowned in fishing nets and may suffer when wetlands and lakes are contaminated by pesticides. Like other fish-eating birds, Red-breasted Mergansers may be persecuted by owners of fish farms and by fishers, who claim that they deplete fish stocks. Poorly sited wind energy facilities also pose a threat. Trivia * The Red-breasted Merganser breeds farther north and winters farther south than the other American mergansers. * Red-breasted Mergansers don't acquire breeding plumage until they are 2 years old. * Red-breasted Mergansers need to eat 15 to 20 fish per day, which researchers suggest means they need to dive underwater 250–300 times per day or forage for 4–5 hours to meet their energy needs. * The oldest recorded Red-breasted Merganser was a female, and at least 9 years, 6 months old when she was shot in Alaska, the same state where she had been banded. * In Spanish, Red-breasted Mergansers are called Serreta Mediana and Harle huppé in French. Sources * “Red-Breasted Merganser Overview, All About Birds, Cornell Lab of Ornithology.” Overview, All About Birds, Cornell Lab of Ornithology, https://www.allaboutbirds.org/guide/Red-breasted_Merganser/overview#. * “Red-Breasted Merganser.” American Bird Conservancy, https://abcbirds.org/bird/red-breasted-merganser/. |-| Gallery = =Gallery= Videos File:Red-breasted Merganser File:Red-breasted Merganser - Ramsgate Harbour, Thanet File:RED BREASTED MERGANSERS HAVING A WASH File:Red-breasted Merganser courtship dance Images Female Sawbill.jpg|Female/immature female sawbill.jpg|Female/immature male mergansers.jpg|Males in flight immature merganser.jpg|Immature male mergansers.jpg|Females sawbills.jpg|Flock in flight. Category:Aves Category:Animalia Category:Chordata Category:Science Category:Anseriformes Category:Anatidae Category:Mergus Category:Birds of North America Category:Birds of the Americas